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My last and final post

Denis — Fri, 15 Jan 2010 18:38:21 +0000

Not that anyone is likely to notice, but this will be my final post. The reason is quite simple; I don’t want to invest a lot of my time writing something that is maybe read by a person once or twice per year. I have started another blog at the local blogging web site and I am getting lots of visits there, probably more in a day than I have gotten here in the entire time since this blog has been up. It would be hard to say what didn’t work out, but I simply got discouraged after making a couple of posts and only receiving two replies, one of which was a spam.

In any case, I wish this turned out different, but that’s life. Enjoy yours.

Dokken – a band often overlooked

Denis — Mon, 14 Sep 2009 09:27:17 +0000

I’m a big fan of everything that came out of 80′s, music particularly. Despite listening to 80′s music for ages, it was only recently that I came across a song from Dokken. I’m not really sure which one it was, but it got me interested enough to get the others as well. Some of them are just damn awesome, my favourite being Breaking the Chains. Video is a typical 80′s rock video, but the music is great.

Despite having sold more than 10 million albums worldwide (or so the Wiki says), I’ve never heard about them before. That is also the main reason I’m writing this and hopefully, I’ve just saved you years of being oblivious.

RentACoder and other freelance sites

Denis — Tue, 01 Sep 2009 11:15:20 +0000

I’ve accidentally stumbled upon a page (RentACoder in my case) where freelancers can find jobs that others have posted. As I was curious, I’ve browsed a little and to my surprise, some projects were actually quite interesting. Being curious (and cautious), I’ve searched for other similar pages. It turns out, there are tons of them. However, I’ve quickly realized the following:

on all pages that I’ve visited (roughly10 or so), 80% of the bidders are Indians.
there are lots and lots of “kids” making offers with comments like:”Get it done !!”, “Sir see pm plz”, “Hi.. We are interested in your project. Please check PMB. Thanks”, “Ready to start now” and “Hello, We offer best Quality”. There’s seriously a shit load (pardon the expression) of stupid comments like that. How is someone supposed to trust you with a project worth 10.000$ and more, if you can’t even spell a single sentence right, not to mention the fact that you have posted the exact same message on just about every other project there is. It’s just unbelievable.
a lot of buyers are posting projects that are clearly out of this world:”Please, I need a clone of Twitter, urgent, start right away, 5 days deadline, 50$ budget”. I wouldn’t even take a piss for 50$ (pardon again), yet this guy wants me to do a major website clone overnight. This is a real project request, I didn’t make it up, and if you’ll browse through some of them, you’ll see that it’s certainly not the only one.
all the pages usualy take 10%-15% of your profit for themselves.
if a page doesn’t at least offer (if not enforce) an escrow payment, don’t (and I really mean don’t) bother with it.

The point being, you have to look really hard to find something worth considering (unless you’re into web pages and iPhone, as just about every project seems to be about one or the other).

I did find the RentACoder best of them all, though. It seemed to have the least number of phony projects and didn’t seemed to be swarming with Indians. Not that I have anything against them, but posting bids on freelancing pages seems to be a national hobby over there. It’s also impossible for me to compete with them, as their prices are generally half as low as mine, yet most of them are equally capable as me or other coders from the rest of the world.

After looking for a while, I’ve found a project that required the implementation of the A* algorithm. Since geometry and algorithms are one of my strong points, I’ve quickly jumped on it and my bid was actually accepted. I was thrilled. Two days later, I’ve earned my first 100$ (minus the 15% they took) and the buyer went even beyond and gave me a bonus as well. It was simply fantastic. Yesterday, I’ve found a project that needed some text translated from english to slovenian. I’ve gotten that one too and I’ve just finished it an hour ago. Wonderful.

I’ve preety much given up looking at pages other than RentACoder. I really do suggest you start with it first and once you find that there is nothing left for you to do at the moment, go check the others. In case you’re wondering, here are the top three I would recommend:

You probably won’t be making a living from them, but a little extra money never hurts. Just be sure to pick something that you can accomplish in a reasonable amount of time (and of course finish it as well).

Wii emulator that works

Denis — Thu, 13 Aug 2009 07:53:52 +0000

I’ve recently bought Wii as a present for my girlfriend. We fell in love with it right away. However, there are certain Wii games that you can only play alone. A Wii emulator seemed to be the best way to play something alone while still enjoying all the Wii action when playing together. After a bit of googling, though, I’ve pretty much given up on finding anything useful. Everyone was saying how it couldn’t be done and that it probably won’t be done for another couple of years. Then, by sheer chance of luck, I found the Dolphin emulator.

I thought it was a scam at first; a 5.8MB file for an entire Wii emulator? However, my doubts were gone and I had a big grin on my face when my first game, Legend of Zelda, started up just fine. I’ve tried a few others and they all worked flawlessly, even on my not-so-fast laptop. Sure, it’s not like playing on actual Wii (mostly by the lack of Wiimote, but you can connect one to the PC anyway if you want), but it’s great for experimenting or playing Wii games at work when no one is looking. Of course, since you can run any Gamecube game on Wii, you can run Gamecube games with this emulator as well. Yet another good reason to give it a try.

Home – video about mass pollution

Denis — Thu, 25 Jun 2009 19:46:34 +0000

Something that everyone living in the “civilized” part of the world should watch - Home. A documentary about how we are destroying our own home (earth) without even thinking about it. I’ve often felt that global warming was way over-rated in comparison to how polluted the earth is becoming.

Ruby on Rails IDE – RadRails

Denis — Tue, 23 Jun 2009 18:25:19 +0000

After finally getting Ruby and Rails to work, I’ve started playing around with various IDE’s (Integrated Development Environment). Although there’s nothing wrong with SciTe (it comes standard with the one-click installer), I feel that more is needed once you get past the basic tutorials. This is especially obvious when it comes to debugging and code completion. I’m kinda ashamed to admit that I’ve become spoiled when it comes to code completion and I can’t imagine working without it. In other words, I’m lazy.

Anyway, the first IDE – RadRails. RadRails is basically Eclipse-like IDE for Rails that is added to the Aptana Studio. I’ve never been a big fan of Eclipse. I don’t feel “at home” when using it, there’s just something missing for me and I’m always wary when dealing with Eclipse plug-in’s. RadRails, apart from the familiar Eclipse looks, offers debugging (even profiling with the pro version, which probably is pro expensive as well), all sorts of editors (CSS, JS, SQL, …), code completion, testing, integrated server and so on. All in all, it doesn’t seem like a bad choice. There are, however, two quirks that I’ve came across. Firstly, a couple of exceptions were thrown during the installation. Clicking the retry button a couple of times seems to have solved it, but who knows what did or didn’t get installed properly. Secondly, HTML source code viewer is bugged. Instead of showing me the code, all I get is a black screen with mysterious white lines appearing everywhere I click. Here’s a picture to show what I mean.

A bugged HTML code viewer.

Not exactly a serious problem since there’s an easy way to fix it (just hit the Add new preview button and you’re done), but it becomes annoying after some time. Still, with so little choice when it comes to IDE’s, you should at least give it a try, especially if you’re already familiar with Eclipse. Personaly, I’ll stick with NetBeans for now (a review is coming after RubyMine).

Next time, RubyMine, the most intelligent Ruby IDE (or so they claim). See you then.

How to update RubyGems

Denis — Sat, 20 Jun 2009 11:29:56 +0000

In my previous post, I’ve commented on how hard it was to manually install Ruby on Rails. The easiest solution was to grab the 1-Click Rails Installer. However, 1-Click Rails Installer doesn’t come with the latest Rails or RubyGems version.

Updating Rails is a no-brainer: just use gem install rails and you’re done with it.

Updating RubyGems is easy as well, once you figure it out. If you try to start the server using updated Rails version but with outdated RubyGems, you will be told to update your RubyGems with the command gem update –system. This, however, doesn’t work. The two commands that will update your RubyGems are gem install rubygems-update, followed by a update_rubygems command. This will then remove the old version and install the new one. Starting the server afterwards will happily work and you’re ready good to go.

Apparently, this works on Mac as well.

Note: If you’re in Vista, you must start the command prompt as administrator. Under Mac/Ubuntu, use the sudo for both commands. I haven’t tried it on any other linux flavour so far, but I’m guessing that logging in as root will do the trick.

I’ve tested this when updating Rails from version 2.1.0 to 2.3.1 and RubyGems from version 1.1.1 to 1.3.4

The Story of Stuff

Denis — Sat, 06 Jun 2009 11:43:09 +0000

The Story of Stuff is a short, 20min movie that tries to show a bigger picture of our every day consumption of everything. To anyone living outside the US, most of the facts presented in the movie are nothing new. The real problem lies, as always, in a country responsible for most of the problems of todays world. If you don’t know which country I mean, you’re probably living in it.

Anyway, here’s the link to the movie: http://www.storyofstuff.com/. Do take a moment to watch it and think about it. It might not change your way of living, but hopefuly, it will change your way of thinking.

Ruby on Rails making your life easier? I don’t think so.

Denis — Tue, 02 Jun 2009 15:08:50 +0000

I’ve heard so many good things about Ruby and Rails. How it will make web design a breeze, how easy it is to use and learn etc. As I’ve been using JSP and JSF in my last project, I was really excited to try and learn something new and more easy to use. JSP was just a pain when things got more complex. I’ve went through a couple of online examples, even tried the interactive online Ruby interpreter and everything seemed straightforward. Then I’ve tried installing it. The damn thing took almost a week before I’ve finally gotten a Hello world web page up using Rails. Gem packages would always whine about missing dll’s, so did MySql. Only after giving it up on MySql and installing SQLite did I get the thing to work.

Spending a week just for a proper installation doesn’t sound like making my life any easier. It was making my life a living hell. It has totally put me off and it’ll take a couple of days/weeks or another JSP project before I get the excitement back up again. It wasn’t so much of a Ruby’s fault as I’ve managed to get it working preety much right away. Getting Rails to work was just a pain. 1-click-Rails installer did the job just fine, but I wanted to install it manualy, which in Rails’ case, is a pain in the butt.

Simple per vertex shading using OpenGL

Denis — Mon, 19 Jan 2009 21:28:08 +0000

Per vertex shading, otherwise known as Gouraud shading, helps us achieve smooth shading results with relatively low computational demands. The idea is really simple, yet I haven’t seen a lot of information about it on the Internet, so I’ve decided to post about it myself.

Let’s imagine we want to display a simple 3D model using OpenGL. The model is made up from a large number of triangles or quadrilaterals (quads). I’ll refer to both as faces from now on. If you want to do any kind of shading, the first thing you need to do is calculate the normal of each face. A normal is simply a vector that is perpendicular to the face (imagine an arrow pointing outwards from the face). However, since we calculate each normal of face independently from other faces, the boundaries between the faces are very noticeable. This ruins the effect of a smooth surface as shown on the following image of a DC-10. You can very easily see the faces that make up the plane.

DC-10 model without per vertex shading

The process of calculating vertex normals is as follows: after we’ve calculated (and normalized) a normal vector for every surface of our object, we iterate through all the vertexes. For each vertex, we determine all neighbouring polygons. In other words, we have to find all the polygons that contain our given vertex. There are many approaches to this. There is of course a brute force approach where you check every vertex against every polygon. Although this might do for simple object or as part of a preprocess one time calculation, it’s not very practical. A better approach is to store neighbouring information for each polygon. If you can’t afford that, you could also generate a bounding box or a bounding sphere for each face. Looking for neighbouring polygons should be simple afterwards.

Anyway, after we’ve found the neighboring polygons, we have to calculate the average of all of their normal vectors. This is again very simple to do. Just separately sum up all the X, Y and Z values of all neighboring polygons and then divide by the number of such polygons. Save this averaged normal vector to our current vertex, repeat for all the remaining vertexes and you’ve just done your first per vertex shading. When it comes to the actual drawing, use glNormal3f(nx, ny, nz) before each glVertex3f command (with nx, ny and nz obviously being individual values that make up the normal vector). The result? A much smoother looking object. Add couple of textures and you’ve got yourself a nice looking model.

DC-10 model with per vertex shading

As we’ve seen, per vertex shading is very easy to do and offers nice results. However, when working with animated models, per vertex shading (as shown above) is totally useless as it’s simply not fast enough for any real-time animation (short of displaying a rotating cube in empty space). Vertex programming is the magic word when we want more advanced results. If you want to do it using OpenGL, take a look at the NV_vertex_program (or vertex shaders if you fancy DirectX). You should note that any serious shading done today is directly on the GPU. Most other methods are for educational purposes only as they help to explain certain graphical and geometrical principles. A topic for one of my future posts maybe. In the mean time, have fun with the above tips. If I haven’t explained it in enough detail, let me know and I can paste some actual code.

Denis